3D hybrid imaging radar system

Abstract

The present invention relates to an imaging RADAR system (100) for imaging a 3D circumference, comprising a RADAR module (10) with at least one RADAR electronic unit (11) and at least one antenna array (12), and comprising a rotation unit (13) for rotating at least one RADAR beam (14). According to the invention, the RADAR module (10) is a at least 2D imaging system (15) and is arranged to the rotation unit (13), so that the RADAR module (10) rotates with the RADAR module (10) and delivers 3D image data by rotating the at least 2D imaging system (15). The invention further relates to a method for operating such an imaging RADAR system (100).

Description

[0001] 3D HYBRID IMAGING RADAR SYSTEM

[0002] DESCRIPTION

[0003] The present invention relates to an imaging RADAR system for imaging a 3D circumference, comprising a RADAR module with at least one RADAR electronic unit and at least one antenna array, and comprising a mechanical rotation unit for rotating at least one RADAR beam. The invention further relates to a method for operating such an imaging RADAR system.

[0004] PRIOR ART

[0005] RADAR sensors are an equipment usually known from prior art for radio-assisted location and distance measurement on the basis of electromagnetic waves, hereinafter called the RADAR beam, in the radio frequency range, in particular at 5 GHz to 500 GHz. For this purpose, RADAR sensors comprise a radio frequency transmitter for irradiating so-called primary signals and a receiver for radio frequency signals that detects the echoes reflected by objects in a certain distance as so-called secondary signals. The receiver and the transmitter are frequently configured as a combined transmission and reception unit, hereinafter called the antenna array.

[0006] Depending on the RADAR operating method, the primary signals are signal pulses or a continuous wave signal that is optionally frequency modulated. Time-resolved information on the relative location, i.e. distance and viewing angle, with respect to the objects reflecting the primary signals can in particular be determined from the reflected secondary signals in 2D or in 3D manner.

[0007] RADAR sensors are today used for process monitoring and process control in a plurality of industrial applications, for example in heavy industry, in particular in mining, construction in agriculture, or on on-road and off-road vehicles, in the handling of goods at ports and logistics centers. In comparison with competing processes based on laser signals or ultrasound signals, RADAR technology is in particular suitable for field deployment under rough conditions since the longwave radio frequency signals used only insignificantly interact with potentially interfering objects such as grains of dust or raindrops.

[0008] RADAR sensors typically comprise a housing, mostly called the radom, in which the sensitive electronic components, in particular the antenna array, are arranged in a protected manner, but the material of the radom is transmissive for RADAR frequency.

[0009] A RADAR sensor known from the prior art for monitoring a field of view measuring up to 360°, mostly of at least a hemisphere, works on the basis of primary signals whose radiation direction rotates about a fixed axis of rotation, wherein a field of view to be monitored is swept over by 360° during a full revolution. The irradiation of the primary signals typically takes place radially to the axis of rotation. With respect to the axis of rotation as the vertical direction, the irradiated primary signal therefore sweeps over a horizontal angle of up to 360° with an unchangeable zenith angle of 90°. In practice, the finite beam divergence of the primary signal results in a beam expansion as the distance from the transmitter increases, whereby the spatial resolution and angular resolution of the RADAR measurement are impaired. The limited solid angle of the monitored field of view that makes the use of a plurality of differently positioned RADAR sensors necessary is a disadvantage with such RADAR sensors of the prior art.

[0010] Document DE 20 2018 106489 U1 discloses a RADAR sensor comprising a frame, a housing rotatable about a pivot axis and arranged at the frame and an antenna unit disposed within the housing for irradiating a RADAR beam in a radiation direction rotatable about an axis of rotation, the radiation direction being substantially orthogonal towards the axis of rotation. This makes it possible to increase the solid angle that can be scanned by the primary signal of the RADAR sensor about 360° in that the housing, and thus also the transmitter, is pivotably supported, whereby the axis of rotation about which the radiation direction of the primary signal rotates, and thus the field of view monitored by the RADAR sensor, can be tilted. On an incremental tilting of the axis of rotation with respect to the starting position and on a (periodic) 360° rotation of the radiation direction of the primary signal about the axis of rotation, a large solid angle can thus be scanned by the primary signal.

[0011] DE 102004034429 A1 discloses a RADAR front end for a motor vehicle comprising the following: a signal source, a plurality of transmitting elements operatively connected to the signal source via a switching matrix which is designed to sequentially supply the transmitting elements with a transmitting signal; at least two receiving elements, whereby the transmitting elements being spatially arranged between the receiving elements, and a device for digitally controlling and processing the receiving signals of the receiving elements, the receiving signals being supplied in parallel to the device. The advantages include, that the potential to cover multiple functions of forward-facing automotive environmental sensors; the transverse resolution in an electronic manner with moderate (compared to phased arrays) expenditure on high-frequency components; the simple and cost-effective antenna technology compared to a differential lobe method; a bandwidth-independent angular resolution with moderate hardware expenditure; the maximum utilization of the available horizontal aperture for transverse resolution; the high flexibility, namely the possibility of adapting the sampling rate and sampling sequence of the transmitting elements to the imaging requirements; the maximum bandwidth efficiency through FMCW methods; the optimum target dynamic range through coherent integration in the distance and angular direction; the improvement of the target dynamic range through the elimination of receiver-side amplitude interference with a heterogeneous receiving structure; the simple connection of a remote receiving element to extend the angular range to ±90° and the optional use of coherent triangulation methods for very short distances, namely parking assistance at distances of less than 1 m; and the low degradation of the imaging quality due to tolerances and changes in the installation environment or due to contamination of the antenna surface.

[0012] Existing pencil-beam RADAR scanners measure one-dimensionally. This allows measurement in one direction with a very high measuring rate, but the high possible measurement rate of the 1 D RADAR can be used for 2D RADAR. In this system as described above, by a rotating parabolic mirror the RADAR signal is deflected so that a 360° measuring plane is created. A further extension into a 3D space is no longer possible, however, if the required minimum measuring rate of minimum measuring rate of 20Hz per spatial direction is to be maintained. Thus, a new concept becomes necessary.

[0013] This principle makes it possible to provide 3D image data, but the imaging takes long time and is limited by the rotating time of the housing about the axis of rotation and leads to a slow scanning result about e.g. a hemisphere.

[0014] DISCLOSURE OF INVENTION

[0015] It is an object of the present invention to provide an improved 3D image system having a fast-scanning principle at least over a hemisphere, here referred as a hybrid RADAR from its technical design architecture.

[0016] This objective is achieved by a RADAR system as taught by claim 1. Advantageous embodiments of the inventive system and the method for operating the system are defined in the further claims.

[0017] The system according to the present invention relates to the technical teaching that the RADAR module is at least a 2D imaging system and is arranged to the rotation unit, so that the RADAR module rotates with the RADAR module and delivers 3D image data by rotating the at least 2D imaging system. In the sense of the invention the at least 2D imaging system can be formed as a 2D imaging system or it can also be formed and / or designed as a 3D or -in other words- a multi- dimension imaging system. The imaging system may capture at minimum range and cross range data (like a 2D section / profile). The imaging system may form a so called DBF Radar, what describes a Digital Beam Forming system, but also phased arrays may be applied. Phased arrays comprise multiple transmitters with a parallel controllable phase shift for a RADAR beam steering.

[0018] The core innovation is the use of a high resolution at least 2D RADAR antenna array which is in total received on a rotating unit to generate the third dimension by the rotation itself, in order to provide a hybrid technology setup of a multi-dimensional digital beamforming RADAR antenna array providing at least range and cross range information- combined with a rotation unit. As an example, with an antenna array having just four receiver channels, three areas with one target each can already be distinguished at the same range in the measuring plane, with additional RADAR antennas and dedicated electronic units correspondingly more. As modern RADAR components already support very high measurement rates, the measurement plane can according to the invention be rotated from measurement to measurement. In this way, a 3D RADAR image is obtained, consisting of individual sharp 2D sectional planes with a high resolution. In other words, with the combination of a mechanical beam moving and an electronic beam forming design is provided a hybrid imaging RADAR system that provides an improved 3D image system having a fast-scanning principle at least over a hemisphere, here referred as a hybrid RADAR from its technical design architecture.

[0019] According to an advantageous embodiment, the rotation unit is rotatable attached to a basic unit, whereas with or inside the basic unit is arranged a RADAR data processing unit.

[0020] The energy and data transfer between the basic unit and the rotating unit is preferably performed wireless. As a preferred embodiment, an electromagnetic energy transmission means is arranged in between the rotation unit and an excitation coil received by the basic unit and an induction coil received by the rotation unit are arranged face to face while the induction coil is rotatable with the rotation unit and the excitation coil rests static in the basic unit. This principle with the excitation coil as a stationary primary coil and the induction coil as the rotating secondary coil enables the transmission of energy by a transformer principle, whereas the coils are ring-shaped and face to face in their side direction. The ring- shaped coils both have a symmetry axis that falls together with the rotation axis of the rotation unit.

[0021] With regard to a data transfer, it is also possible to use an electromagnetic transmission means which is arranged in between the rotation unit and the basic unit comprising an excitation coil and an induction coil, in particular when a transmission signal is modulated. But for the present purpose and the need of high data transmission speed and a high data transmission rate, the data transmission according to the invention bases on an optical means.

[0022] In this respect, a data transmission means is arranged in between the rotation unit and the basic unit comprising first optical fiber which is attached to the basic unit and a second optical fiber which is attached to the rotation unit, whereas both optical fibers are arranged face to face for a data transmission between the RADAR data processing unit deposited in the basic unit and the RADAR electronic unit in the rotation unit. The optical fibers extend in the axis of rotation in particular in the section next to their end faces, which are arranged face to face and are spaced apart by a small air gap. The optical data transfer is not influenced by the rotating of the second optical fiber which is attached to the rotation unit.

[0023] In order to cause the rotation in the rotation unit, the system comprises an electric motor which is received in the basic unit and is coupled with the rotation unit for rotating the same. The electric motor is preferably designed as an outrunner and has a stator which is arranged on the basic unit and which is enclosed by a potshaped or bell-shaped rotor, preferably made by deep drawing. An electrical winding is installed in the stator and internal magnets are arranged at the inner side of the stator. The stator itself is designed with a cylindrical cavity that coincides with the axis of rotation of the rotating part. This enables the centric arrangement of the optical fiber. As another feature, it can be an advantage to control the electric motor by the RADAR electronic unit which is arranged in the rotation unit in order to combine the control of the rotation movement of the rotation unit in conjunction with the RADAR control of the 2D imaging system rotating with the rotation unit. Therefore, as an alternative, the motor winding can be mounted in the rotating part and rotates together with the antenna and the RADAR electronic unit, while the stator contains the magnets and rests unmoved in the basic unit. With another advantage, the motor forms an outrunner type motor.

[0024] The electric motor is formed to rotate the rotation unit comprising the RADAR module by 10Hz to 50Hz, preferably by 20Hz to 30Hz and most preferred by 25Hz. This rotation speed of 25 revolutions per second, or 1.500 revolutions per minute enables the fast scanning of the circumference and can be processed by the RADAR data processing unit within the basic unit.

[0025] The antenna array is formed in such a way that the RADAR beam features a usable beam opening angle of about or in the range of 120°. The beam opening angle of 120° describes a beam cone of 2x60° with respect to the beam center. The beam actually exceeds the ±60°, however the signal intensity and quality is dropping towards ±90° rapidly, so the sector beyond is commonly discarded. The rotation unit features a receiving frame to which the antenna array is attached at the upper side, whereas the receiving frame features an angle of at least 30° relative to the vertical rotation axis, so as to make sure that at least a hemisphere is covered by the scanning area. The angular resolution drops with the cosine to zero at 90° at around + / -600and the resolution becomes fast worse and mostly effects of the RADAR housing start to disturb, as the side of the housing is often a little higher than the antennas.

[0026] With regard to the measuring principle, it can be used a coherent radar. This means that every measurement fulfils the same initial condition. The measurements always start with the same frequency and the same modulation, all receivers run synchronized relating to the start of the measurement.

[0027] A radom is arranged to the basic unit covering the rotation unit comprising the RADAR module, and the RADAR beam enters through the radom. The radom, e.g. made of polybutylenterephthalat (PBT), which material features good transmission values for the RADAR beam. Radom materials are typically selected by the transmission defined by the dielectric constant (dk-value) as well as the mechanical properties like stiffness or UV protection - so often as well Polytetrafluoroethylene (PTFE) or Polycarbonate (PC) can be used as well. According to yet another preferred aspect of the inventive method the RADAR antennas are operated by FMCW RADAR technology in a frequency range of at least a part of the E-band and / or in a frequency range of 60GHz to 90GHz or 75GHz to 85GHz and / or 76GHz to 81GHz, 122GHz to 130GHz, 134GHz to 148,5GHz or 244 GHz to 246 GHz. The band width can be 1GHz to 5GHz. A range of 8GHz, 10GHz or 14,5GHz can as well be considered. When the RADAR system relates to an additional applied ultrawideband (UWB) system, the RADAR frequency can also range from 57GHz to 64GHz or specifically 33.4GHz to 36 GHz. With changing frequency legislation other yet unknown frequency ranges and bandwidth can be used. The frequency selection is mainly driven by frequency regulation.

[0028] In general, the FMCW method describes a family of modulations, and in particular the "ramp method" is generally known, which can be applied here. The measurement starts from a defined lower transmission frequency and increases linearly over time up to its upper limit. The measurement is then completed. The ramp could just as well run from top to bottom downwards or runs in a triangular shape. Sometimes frequency hopping is added. The ramp or the triangle can be divided into several sections of equal length or can be diced in a jumble. On the one hand, this is intended to increase interference immunity and, on the other hand, to deliver the doppler-speed more quickly, although latter may depend on available computing power.

[0029] It can be used a digital beamforming array combined with a phased array. The latter does not have to be used, but can be used, which has advantages and disadvantages. The advantage is a higher transmission power in one direction, i.e. greater range in one direction, but the disadvantage is a less range in other directions. By repeating the measurement with a different phase position for the transmitters, a different direction can be emphasized. On the receiving side it is used a digital beamforming process for image generation. Therefore, this is deliberately reduced to 2D. The digital beamforming describes an electronic beam steering and phased array having several transmitter channels and they may be combined to increase power, and more transmitter channels also lead to more direct the transmitter beam. It can be used as so-called phased arrays. On the other hand, the receive side stays a digital beamforming array.

[0030] The aforementioned method enforces a certain antenna arrangement, in particular at least a 2D antenna array on the transmitting as well as on the receiving side, and the 3rd dimension comes from the rotation. How these antennas are designed is initially irrelevant, they can be patching antennas, lens antennas, horn antennas, or something else, or a combination of these. It can be used a plate antenna with a lens, which can be made as a compact 3D metal print part with Teflon inserts. This promises the most compact arrangement with good sidelobe-free focusing of the radar beam. A 3D image is then created by the vertical half-sided 120° cuts made around the circle of rotation.

[0031] The invention also includes a method for operating an imaging RADAR system comprising a RADAR module with at least one RADAR electronic unit and at least one antenna array, and comprising a rotation unit for rotating at least one RADAR beam, whereas the method comprises at least the following steps: providing the RADAR module as a 2D imaging system, arranging the RADAR module to the rotation unit, rotating the RADAR module with the antenna array and providing 3D image data by rotating the at least 2D imaging system. In other words, the third dimension is caused by rotating a 2D scanning line with a beam opening angle of 120° around a rotation axis and the scanning area extends at least across a hemisphere.

[0032] As a fourth dimension the velocity of a target object can be measured, using different signal generation and signal processing methods like range-doppler, doppler, phase differences and so on, while the fourth dimension relates to the time passed and thus a displacement of an object in a three dimensional space. This can as well be combined with tracking (like Kalman filters, SLAM (simultaneous localization and mapping), CFEAR Radarodometry (Conservative Filtering for Efficient and Accurate Radar Odometry) or particle filters and additional object meta data can be generated. This can be also applied in conjunction with the at least 2D imaging system and calculated by means of the RADAR module. The rotation unit is rotated by 10Hz to 50Hz, preferred by 20Hz to 30Hz and most preferred at 25Hz. The antenna array generates a RADAR beam preferred with a FMCW RADAR technology in a frequency range of at least a part of the E-band and / or in a frequency range of 60GHz to 90GHz and / or 75GHz to 85GHz and / or 76GHz to 81GHz and / or 57GHz to 64GHz, 122GHz to 130GHz, 134GHz to 148,5GHz or 244 GHz to 246 GHz.

[0033] Preferably the at least 2D imaging system features input channels and output channels, forming a so-called Ml MO-System (Multiple Input Multiple Output), although it only may use one transmitter, but certainly more than one transmitter can be used. The environment is thus measured in spherical coordinates, namely by a distance and a longitudinal angle from the MIMO array (vertical) and lateral from the rotation angle (horizontal).

[0034] The antenna array may feature exactly one transmitting antenna or a discrete number of transmitting antennas which are operating with an identical signal and the antenna array may feature a number of receiving antennas each receiving the discrete signal. The number of receiving antennas typical exceeds the number of transmitting antennas defining the resolution.

[0035] The rotation unit comprising the RADAR module rotates in a rotation axis and the electric energy transmits via the electromagnetic energy transmission means which is arranged in between the rotation unit and the basic unit. Moreover, the RADAR data (raw data sampled from the ADC analogue digital coupler) exchanges via the first optical fiber attached to the basic unit and the second optical fiber attached to the rotation unit while rotating the rotation unit. Alternative to a raw data transfer over the optical fiber it is as well possible to have a design variant with a preprocessing (like FFT and / or CFAR) in the RADAR module on the rotating part like with a FPGA, a DSP, a CPU or a GPU. With such a means in the rotating part a FPGA that controls and receives the signals, it is possible to transfer the data with e.g. a 10Gbit / s ethernet link optionally using forward error correction to improve stability, and in the base unit can be arranged a GPU processing unit. Modern FPGAs embedding additionally a number of processors and one or many Al cores also can be used. The FPGA, a so called field programmable gate array, also controls the rotation speed of the rotating unit and reads the rotation angle synchronous to the RADAR measurement by the RADAR electronic unit.

[0036] PREFERRED EMBODIMENT OF THE INVENTION

[0037] The aforementioned features of the system, as well as the claimed components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their succession of steps, the size, shape, the material selection and / or the technical concepts such that the selection criteria known in the pertinent field can be applied without limitations.

[0038] Additional details, characteristics and advantages of the object of the invention are disclosed in the sub claims and the following description of the respective figures shows preferred embodiments of the system and the method according to the invention. It is shown in:

[0039] Fig. 1 a cross section of the hybrid imaging RADAR system according to the invention with the basic unit, the rotation unit and the RADAR module attached to the rotating unit;

[0040] Fig. 2 a cross section of the upper part of the basic unit comprising an electric motor, bearings, an energy transmission means, and a data transmission means to enable a free rotation of and to interface the rotation unit and

[0041] Fig. 3 a perspective view of the entire hybrid imaging RADAR system according to the invention.

[0042] Figure 1 shows a cross-sectional view of the hybrid imaging RADAR system 100 for imaging the circumference by 3D data provided by the system 100. The system 100 comprises a basic unit 16 and a rotation unit 13, and the rotation unit 13 is rotatable received on top of the basic unit 16 to rotate about a rotation axis A. To the rotation unit 13 is attached a RADAR module 10 in such a manner that when the rotation unit 13 is rotating about the rotation axis A, the entire RADAR module 10 rotates with the rotation unit 13, e.g., with 25Hz. When the RADAR module 10 is operating, the module 10 provides a RADAR beam, and accordingly the RADAR beam also rotates about the Rotation axis A.

[0043] The RADAR module 10 is performed as an at least 2D having a digital beam forming (DBF) imaging system 15 and is arranged to the rotation unit 13, so that the RADAR module 10 rotates with the RADAR module 10 and delivers 3D image data by rotating the 2D imaging system 15. This makes it possible to use a high resolution 2D RADAR antenna array 12 which is totally received on a rotating unit 13 to generate the third dimension in the provided RADAR data only by the rotation about the rotation axis A.

[0044] The RADAR module 10 is received on the rotation unit 13 by means of a receiving frame 23, which receiving frame 23 is designed in such a way that at least the RADAR antenna array 12 of the RADAR module 10 is inclined relative to the rotation axis A, butt a not inclined arrangement is also possible. The RADAR beam (not shown) can for example feature an overall beam opening angle of 120°. When the RADAR module 10 comprising the RADAR antenna array 12 rotates about the rotation axis A, the circumference can be imaged with the rotating 120° opened RADAR beam. The inclination of the receiving frame 23 is correlated to the beam opening angle of the RADAR beam in such a way that at least a closed hemisphere can be imaged and provided by the provided data. These image data can be processed in a RADAR data processing unit 17 which is received in the lower part of the basic unit 16. The upper part of the basic unit 16 is shown in more detail in the following figure 2.

[0045] In figure 2 is depicted the upper part of the basic unit 16 for interfacing the rotation unit 13, on which the receiving frame 23 carrying the RADAR module 10 can be mounted as shown in Figure 1. In order to rotate the rotation unit 13, which features a receiving face 27 on the upper side, to which the receiving frame 23 can be mounted, the basic unit 16 comprises an electric motor 22. The electric motor 22 comprises a stator 24, and the stator 24 forms the not rotating inner part of the motor 22. The motor 22 is preferably brushless, so it does not cause wear and allows a maximum service life. The rotor 25 rotates about the rotation axis A in the bearings 29 and receives the stator 24 within the inner side of its bell-shape. The rotation unit 13 is dynamic balanced, so that the rotation will not cause vibration or shaking of the RADAR. The two bearings 29 have an increased diameter for stability and torque transfer and are preloaded against each other to achieve very good rotational guidance, so that this also has a positive effect on the quality of the RADAR data obtained.

[0046] The electric motor 22 is designed as an outrunner and the stator 24 is arranged on the basic unit 16 which is enclosed by a pot-shaped or bell-shaped rotor 25. An electrical winding is installed in the stator 24 and internal magnets 26 are arranged at the inner side of the bell-shaped rotating rotor 25. The stator 24 itself is designed with a cylindrical cavity. The construction of the electric motor 22 is also called an outrunner motor. Alternatively, the part with the winding can be mounted at the rotational part and the stator with the magnets is fixed mounted on the basic part.

[0047] In order to transmit electric energy from the basic unit 16 to the rotation unit 13, the basic unit 16 comprises an electromagnetic energy transmission means 18. This means 18 makes it possible to transmit electric energy from a not rotating part to a rotating part and is designed wireless. The electromagnetic energy transmission means 18 comprises an excitation coil 19 received by the basic unit 16 and an induction coil 20 received in the rotation unit 13. Both the excitation coil 19 and the induction coil 20 are arranged face to face in a side direction, while the induction coil 20 is rotatable within the rotation unit 13 and the excitation coil 19 rests in the basic unit 16. When the excitation coil 19 is operated by alternating current, the induction coil 20 receives the electric energy by induction, and the induced current can be used to supply the rotation unit 13 and thus the RADAR module 10 with energy.

[0048] According to another aspect, a data transmission means 21 is arranged in between the basic unit 16 and the rotation unit 13. The data transmission means 21 enables the wireless transmission of RADAR data provided by the RADAR module 10 arranged to the rotation unit 13 down to a RADAR data processing unit received in the lower part of the basic unit 16. The data transmission means 21 comprises a first optical fiber 21a which is attached to the basic unit 16 and a second optical fiber 21b which is attached to the rotation unit 13, whereas both optical fibers 21a and 21b are arranged face to face with a small air gap to avoid wear and abrasion allowing data transmission between the data rate processing unit 17 (see fig. 1 ) in the basic unit 16 and the RADAR electronic unit rotating with the rotation unit 13. But there is a small gap between the faces of the optical fibers 21a and 21 b to prevent wear.

[0049] Figure 3 shows a schematic depiction of the entire imaging RADAR system 100 with the basic elements comprising the rotation unit 13 comprising the receiving frame 23 for receiving the RADAR module 10 comprising the antenna array 12 and providing the RADAR beam 14. The rotation unit 13 is received on top of the basic unit 16 and is protected by a Radom 28. The random 28 is transmissive for the RADAR beam 14 but protects the rotation unit 13 and in particular the antenna array 12.

[0050] The antenna array 12 features a discrete number of transmitting antennas which are each operating with a time- and / or profile- identical signal and the antenna array features a number of receiving antennas each receiving the discrete signal. The number of receiving antennas which should significantly exceed the number of transmitting antennas, in particular. In this manner a 2D imaging system 15 is shifted to a 3D system by rotating the entire RADAR module 10. The RADAR beam 14 is only shown schematically and may have an opening cone of 120° opening angle. As an alternative, an approximately vertical 120° opening angle can be applied, which also can be horizontal. The beam is not infinitely focused horizontally either, but it is also possible without it, because the stronger the horizontal focusing of the MIMO array, the heavier and larger wider it becomes.

[0051] Next to the advantages named above, further advantages of the claimed setup are a high range, low side Lobes, high signal-to noise reduction (SNR), higher measurement rate and / or a lower processing power. The present invention is not limited by the embodiment described above, which is represented as examples only and can be modified in various ways within the scope of protection defined by the appending patent claims.

[0052] Reference Numbers:

[0053] 10 RADAR module

[0054] 11 RADAR electronic unit

[0055] 12 antenna array

[0056] 13 rotation unit

[0057] 14 RADAR beam

[0058] 15 2D imaging system

[0059] 16 basic unit

[0060] 17 RADAR data processing unit

[0061] 18 transmission means

[0062] 19 excitation coil

[0063] 20 induction coil

[0064] 21 data transmission means

[0065] 21a first optical fiber

[0066] 21b second optical fiber

[0067] 22 electric motor

[0068] 23 receiving frame

[0069] 24 stator

[0070] 25 rotor

[0071] 26 magnet

[0072] 27 receiving face

[0073] 28 radom

[0074] 29 bearing

[0075] 100 imaging RADAR system

[0076] A rotation axis

Claims

Claims:

1. Imaging RADAR system (100) for imaging a 3D circumference, comprising a RADAR module (10) with at least one RADAR electronic unit (11) and at least one antenna array (12), and comprising a mechanical rotation unit (13) for rotating at least one RADAR beam (14), characterized in that the RADAR module (10) is at least a 2D imaging system (15) and is arranged to the mechanical rotation unit (13), so that the RADAR module (10) rotates with the RADAR module (10) and delivers 3D image data by rotating the at least 2D imaging system (15).

2. Imaging RADAR system (100) according to claim 1 , characterized in that the rotation unit (13) is rotatable attached to a basic unit (16), whereas with the basic unit (16) is arranged a RADAR data processing unit (17).

3. Imaging RADAR system (100) according to claim 1 or 2, characterized in that an electromagnetic energy transmission means (18) is arranged in between the rotation unit (13) and the basic unit (16) comprising an excitation coil (19) received by the basic unit (16) and an induction coil (20) received by the rotation unit (13), whereas both the excitation coil (19) and the induction coil (20) are arranged face to face while the induction coil (20) is rotatable with the rotation unit (13).

4. Imaging RADAR system (100) according to one of the claims 1 to 3, characterized in that a first optical fiber (21a) is attached to the basic unit (16) and a second optical fiber (21b) is attached to the rotation unit (13), whereas both optical fibers (21a, 21b) are arranged face to face for a data transmission between the RADAR data processing unit (17) in the basic unit (16) and the RADAR electronic unit (11) in the rotation unit (13).

5. Imaging RADAR system (100) according to one of the previous claims, characterized in that an electric motor (22) is received in the basic unit (16) and is coupled with the rotation unit (13) for rotating the same.

6. Imaging RADAR system (100) according to one of the previous claims, characterized in that the electric motor (22) is formed to rotate the rotation unit (13) comprising the RADAR module (10) by 10Hz to 50Hz and / or 20Hz to 30Hz and / or 25Hz.

7. Imaging RADAR system (100) according to one of the previous claims, characterized in that the antenna array (12) is formed in such a way that the at least 2D imaging system (15) comprises a digital beamforming and / or the RADAR beam (14) features a usable beam opening angle of 30° to 150° centering 90°.

8. Imaging RADAR system (100) according to any of the previous claims, characterized in that the antenna array (12) is performed to generate a RADAR beam (14) with a FMCW RADAR technology in a frequency range of at least a part of the E- band and / or in a frequency range of 60GHz to 90GHz and / or 75GHz to 85GHz and / or 76GHz to 81 GHz and / or 57GHz to 64GHz.

9. Imaging RADAR system (100) according to one of the previous claims, characterized in that a radom (28) is arranged to the basic unit (16) covering the rotation unit (13) comprising the RADAR module (10), and the RADAR beam (14) enters through the radom (23).

10. Method for operating an imaging RADAR system (100) comprising a RADAR module (10) with at least one RADAR electronic unit (11) and at least one antenna array (12), and comprising a rotation unit (13) for rotating at least one RADAR beam (14), whereas the method comprises at least the following steps:characterized in that- providing the RADAR module (10) as an at least 2D imaging system (15);- arranging the RADAR module (10) to the rotation unit (13);- rotating the RADAR module (10) with the antenna array (12) and- providing 3D image data by rotating the at least 2D imaging system (15).

11. Method according to claim 10, characterized in that the rotation unit (13) is rotated by 10Hz to 50Hz and / or 20Hz to 30Hz and / or 25Hz.

12. Method according to claim 10 or 11 , characterized in that the antenna array (12) generates a RADAR beam (14) with a FMCW RADAR technology in a frequency range of at least a part of the E-band and / or in a frequency range of 60GHz to 90GHz and / or 75GHz to 85GHz and / or 76GHz to 81GHz and / or 57GHz to 64GHz, 122GHz to 130GHz, 134GHz to 148,5GHz or 244 GHz to 246 GHz.

13. Method according to one of the claims 10 to 12, characterized in that the antenna array (12) features one transmitting antenna or a number of transmitting antennas operating with the same, discrete signal and a number of receiving antennas each receiving the discrete signal.

14. Method according to one of the claims 10 to 13, characterized in that while the rotation unit (13) comprising the RADAR module (10) rotates in a rotation axis (A) the electric energy is transmitted via the electromagnetic energy transmission means (18) is arranged in between the rotation unit (13) and the basic unit (16) and data are exchanged via the first optical fiber (21a) attached to the basic unit (16) and the second optical fiber (21b) attached to the rotation unit (13).

Images